She warned that the human rights of the victims, who were then known as "comfort women", continue to be violated decades after the end of the World War II, Xinhua reported.

"During my visit to Japan in 2010, I appealed to the government to provide effective redress to the victims of wartime sexual slavery," Pillay said in a statement.

"Now, as my tenure in office comes to an end, it pains me to see that these courageous women are passing away one by one without their rights restored and without receiving the reparation to which they are entitled," she added.

Pillay stressed this was not an issue relegated to history as human rights violations against these women continue to occur as long as their rights to justice and reparation are not realized.

Instead of justice, she added, the women are facing increasing denials and degrading remarks by public figures in Japan.
A report, issued by a study team appointed by the Japanese government in June, said that it was not possible to confirm that these women were forcibly recruited.

Following the report, a group in Tokyo publicly declared that comfort women were not sex slaves but wartime prostitutes.

"Such statements must cause tremendous agony to the women, but we have not seen any public rebuttal by the government," Pillay said.

The UN Human Rights Commission, which oversees implementation of the International Covenant on Civil and Political Rights, recently called upon Japan to take immediate and effective legislative and administrative measures to ensure that all allegations of sexual slavery are investigated and perpetrators prosecuted.